fix(mobile): native settings controls + soundboard/gif/call polish (M5)

Mobile-audit batch 5. Desktop provably unchanged (two review passes).

- Translate-language control: raw <select> (crowded narrow tiles + broke under
  non-default themes) -> the folds-native SettingsSelect used by every other
  dropdown in the settings screen (native-cinny; keeps aria-label).
- Ringtone/Soundboard volume sliders: moved from the fixed-width tile `after`
  slot (which squeezed the title on phones) to a full-width slider in the tile
  body, matching the night-light slider pattern.
- Screenshare-confirm popover: clamp maxWidth to the viewport so it can't run
  past the screen edges on a phone (inert on desktop).
- In-call soundboard editor rows wrap on a narrow popout instead of crushing the
  clip-name field.
- GifPicker: feed the giphy Grid the measured container width (useElementSize
  Observer) instead of a fixed 296px, so it doesn't overflow a <312px phone.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/app/features/call/CallControls.tsx

@@ -338,6 +338,9 @@ export function CallControls({ callEmbed }: CallControlsProps) {
               padding: '1rem 1.25rem',
               zIndex: 100,
               minWidth: '260px',
+              // Don't run past the screen edges on a narrow phone (centered via
+              // translateX(-50%)); clamp to the viewport minus a small margin.
+              maxWidth: `calc(100vw - 2 * ${config.space.S400})`,
               boxShadow: '0 8px 32px rgba(0,0,0,0.35)',
               display: 'flex',
               flexDirection: 'column',